【作者】 鲍宇彬；

【导师】 吴驰飞；

【作者基本信息】 华东理工大学 ， 材料材料科学与工程， 2012， 博士

【摘要】 本文采用热降解和超声声化学的方法,结合炭黑捕获自由基的固有特性,制备出了两种不同有机物接枝的炭黑。两种接枝炭黑分别可以在有机溶剂或水中稳定分散。利用接枝炭黑和聚合物微球之间的非共价键作用,以及接枝炭黑和无机棒状黏土之间的静电共凝聚作用,制备出了不同的自组装复合粒子。通过对自组装过程的控制,使制备的复合粒子形成稳定和表面性质可控的结构,利用该结构作为功能性砌块在聚合物基体内部构建有效的导电网络。并通过对炭黑层层自组装特性的研究,制备出了厚度和电性能可控的复合薄膜。文本的主要内容如下：1.使用原位固相接枝的方法制备Irganox1330接枝改性的炭黑(CB)。利用CB表面Irganox1330的苯环与聚苯乙烯(PS)微球模板表面的芳香环产生π-π共轭作用,来简单而有效地制备PS/CB自组装微球。通过调整共凝聚过程中的溶剂极性,对自组装微球的表面结构进行可控构建。使用SEM和AFM对PS/CB自组装微球的形貌进行表征,并利用水接触角对自组装微球的表面性质进行测试。结果证明了通过控制CB在PS微球表面的吸附量,能够有效构建PS/CB自组装微球的表面形貌和性质。2.使用共凝聚方法制备可控形貌的PS/CB自组装微球,并使用SEM观察其表面。分别研究了使用PS/CB自组装粒子制备的CB/PS和CB/PS/PC复合材料的电导性。详细研究了PS含量、自组装粒子上CB的包覆率以及CB的含量对CB/PS/PC复合材料电性能的影响。结果显示,相比一般溶液混合法制备的复合材料,利用PS/CB自组装复合粒子表面形貌变化与电阻率的关系可以有效降低复合材料的渗流阈值。不仅如此,PC/PS材料间的“零双折射”现象增加了复合材料的透光率。3.采用超声降解聚合物的方法制备了具有良好水分散性的聚(甲基乙烯基醚／马来酸酐)(PVM/MA)接枝CB,并使用FT-IR和TGA对其进行表征。Zeta电位分析表明接枝在CB表面的PVM/MA分子具有pH值响应性。利用PVM/MA和聚乙烯亚胺(PEI)在水中带有的异相表面电荷为驱动力,制备聚对苯二甲酸乙二醇酯为基材的接枝CB/PEI层层自组装薄膜,并使用AFM进行表征。薄膜制备过程中的pH值、沉积循环次数和浸没时间影响薄膜的CB厚度。随着薄膜循环数的增加,薄膜材料的透过率以及表面电阻率均出现不同程度的下降。4. PVM/MA接枝CB在水性聚氨酯乳液和固体复合材料中分别具有良好的分散性和界面相容性。HRTEM观察发现表面带有相反电荷的PVM/MA接枝CB和凹凸棒(ATT)之间在水中发生静电共凝聚,接枝CB组装在ATT表面并提高了整个体系的分散稳定性。接枝CB和ATT的质量比影响着两种粒子在水中或者在复合材料内部的分散,这导致了复合材料电学和力学性能的变化。DMA和电阻测试结果表明，当GCB与ATT具有合适的质量比时,复合材料的电学和力学性能同时提高。5.通过溶液混合法制备了ATT/CB/环氧树脂(EP)复合材料。UV-Vis和Zeta电位测试仪对CB和(或)ATT在丙酮溶剂中的分散稳定性进行了研究。使SEM、电阻仪分别研究了不同填料含量以及不同填料比例对EP复合材料微观结构和体积电阻率的影响。结果表明,ATT的加入可以有效增强CB在溶剂中的分散稳定性,促进EP基体中导电网络的形成,并提高材料的储能模量。更多还原

【Abstract】 Combined with the radical trapping nature of carbon black (CB), thermal degradation and ultrasonic degradation methods were used to prepare two different kinds of organic compound grafted CB. Two kinds of grafted CB have good dispersiblity and stability in organic solvent or water, respectively. Take advantage of the non-covalent bond between grafted CB and polymer microsphere, or the electrostatic heterocoagulation between grafted CB and inert clay nanorods to create different self-assembly composite particles. Controllable morphology of composite particles were acted as building blocks in order to create conductive networks with the polymer matrix, and fabricated through tailoring the process of self-assemble behavior of CB. According to the study for layer-by-layer (LBL) self-assemble behavior of CB, the CB/polymer thin film with controllable thickness and electrical property was prepared. The main conclusions are as follow:1. A simple in-situ solid grafting approach was used to prepare Irganox1330 grafted CB. Take advantage ofπ-πinteraction between Irganox1330 and polystyrene (PS) to prepare PS/CB self-assembly microspheres. The morphology of PS/CB microsphere was tailored through adjusting the polarity of heterocoagulation process, and investigated by SEM and AFM. The wetability of PS/CB microsphere was measured by water contact angle (WCA). The results indicated that the morphology and surface property was determined by the CB concentration of PS/CB self-assembly microsphere.2. PS/CB self-assembly microspheres were prepared by heterocoagulation process from grafted CB and PS microspheres through aπ-πinteraction. Their morphologies could be tailored as the coverage dgree of CB on PS microsphere and were investigated by SEM. The CB/PS composites and CB/PS/PC composites prepared by using PS/CB microspheres were investigated. The effects of concentration of PS, coverage degree of CB and concentration of CB on electrical properties were studied. The results showed that, compared with general composites, the percolation threshold of composites could be improved by utilizing the interaction between the morphology of self-assembly microsphere and resistivity. In addition, the zero birefringence of PS/PC blends improved the light transmittance of such composites.3. Polyelectrolyte poly (methyl vinyl ether-co-maleic acid) (PVM/MA) was grafted on the surface of CB by ultrasonically degraded method. FT-IR, TGA were used to analyze the surface properties and structure of PVM/MA grafted CB. The pH-responsive of PVM/MA grafted CB influence the particle size of grafted CB in water. A thin film was frabicated from LBL assembly of grafted CB and polyethyleneimine (PEI) due to different surface charge. AFM was used to investigate the surface morphology of this grafted CB/PEI film. pH value, immersion time and the number of deposition circles affected the film thickness. The light tansmittance and resistivity of film were improved as the increase of deposition circles. 4. PVM/MA grafted CB had better dispersibility and compatibility than that of pristine CB in water-bonre polyurethane (WPU) and corresponding solid composites. DLS and HRTEM results demonstrated that anionically charged grafted CB nanoparticles were heterocoagulated on the surface of cationically charged ATT nanorods and improved the stabilization of ATT in wate as dispersing aids. The microstructure development in matrix that depended on various weight ratios of the nanoparticles ultimately influenced the electrical conductivity and mechanical property of WPU composites. The results showed that both electrical conductivity and storage modulus of composite could be improved simultaneously when CB and ATT had a appropriate weight ratio.5. ATT/CB/Epoxy (EP) composites were prepared by liquid mixing method. The stability of CB and (or) ATT suspensions in acetone was analyzed by UV-Vis and Zeta potential. The microstructures and volume resistivity of the composites were examined by scanning electron microscope (SEM), resistance meter and DMA. The results indicated that ATT can effectively improve the dispersion of CB in solution, which resulted in conductive networks in the matrix and improved storage modulus.更多还原